ABSTRACT
Understanding the mechanisms involved in cellular damage and repair caused by reactive oxygen species (ROS) has evolved, in part, from studies with appropriate bacterial mutants. The need for this information arose from scientic discoveries of x-ray and radioactive isotopes. Unfortunately, the earlier users suffered from these radiations before the mechanisms of biological damage were fully understood. Knowledge and understanding progressed rapidly mainly due to extensive collections of metabolic and regulatory genetic mutants of bacteria and libraries of publications on gene damage and repair mechanisms.
